Electrical circuits are used in a variety of environments that can present particular physical, chemical, and electrical factors for which the circuit must either be protected or be designed to endure. The present invention primarily concerns physical factors such as mechanical stress leading to fatigue, which in turn can cause a circuit malfunction by physically breaking or weakening a specific part of the circuit, A typical location for such malfunction is at or near the point of connection of a wire, lead, or other conductor to an electrical circuit. In circumstances where the wire and the connected-to circuit may move or rotate relative to one another, the wire may incur a concentration of mechanical stress and/or fatigue at or near the point of connection to the circuit. Mechanical stresses such as repeated bending or twisting, for example, can lead to a weakening of the wire until a break occurs.
Electronics integrated within a tire or other product offer potential advantages such as asset tracking and measurement of physical parameters as, for example, temperature and pressure. For purposes of the present disclosure, the phrases ‘integrated within a tire’ or ‘integration within a tire’ denotes any association of an electronics device with a tire including, but not limited to, encased or adhered entirely or partially within or to any portion of the tire, or attached to an inner or outer surface of the tire.
Often many of these systems rely on a wireless data link to communicate with an information system outside of the vehicle. Such information systems may include, as non-limiting examples, on-board computer systems, drive-by interrogators, or hand-held interrogators. In addition, the types of data communicated over such wireless data links are wide and varied and include such as not only the previously mentioned temperature and pressure but also other physical parameters such as tire rotation speed as well as data corresponding to manufacturing data and a host of other information. What ever the type of data transmitted, the wireless data link requires an antenna to be attached to the electronics in the tire. If the electronics and/or antenna are adhered to the tire rubber, flexing of the tire, either due to the tire building process or normal use can cause the antenna to separate from the electronics due to cracking, breaking, or fatigue.
U.S. Pat. No. 7,196,616 (Sinnett et al.) discloses apparatus and methodology for providing a graduated stiffness, strain-resistant electrical connection. A material is configured around the lead and near the point of connection to the circuit so as to create a region of decreasing flexibility or graduated stiffness near the point of connection. Another example of a tire electronics system can be found in U.S. Pat. No. 7,102,499 (Myatt), which concerns an electronic communications device for a tire that includes a radio device and an antenna to be attached to or embedded in a tire.
U.S. Patent Application Publication No. U.S. 2007/0274030 A1 (Robert) also relates to tire electronics, and more particularly discloses an electronic module designed to be incorporated in a tire comprising a functional device, a support and at least one device for electrically connecting a wire and a device for mechanically fixing the wire, separate from the electrical connection device, for mechanically fixing the wire to the support.
The PCT Application published as International Publication Number WO 2006/098710 A1 (Sinnett et al.) is directed to a strain-resistant electrical connection for coupling an antenna or other conductive lead to a circuit.
Other similar subject matter is described in JP2007049351A entitled “Electronic Tag For Tire And Pneumatic Tire” as an electronic tag with a coil-shaped antenna connected to an integrated circuit chip. The coil-shaped antenna includes dual pitch wound portions with the higher pitch winding coupled to the integrated circuit chip. U.S. Pat. No. 6,836,253 B2 (Strache et al.) describes a transmitter or receiver unit for building into elastic structures including tires. The unit may include an antenna taking several forms including a coiled-wire configuration.
The PCT Application published as International Publication Number WO 2009/134243 (Sinnett et al.) is directed to an In-Plane RFID Antenna incorporating a strain-resistant electrical connection for coupling an antenna lead to a circuit. This published application describes a technique similar to that described with reference to the known devices illustrated herein in FIG. 2 and described later in comparison to the present subject matter.
While various implementations of tire electronics devices such as RFID devices in tire electronic systems have been developed, and while various methodologies have been developed to relieve stress at electrical coupling points, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the present technology.